Merge branch '3.x' into HEAD

bin/pt-archiver

@@ -1048,7 +1048,9 @@ sub _parse_specs {
          $opt->{spec} =~ s/=./=s/ if ( $type && $type =~ m/[HhAadzm]/ );
 
          if ( (my ($def) = $opt->{desc} =~ m/default\b(?: ([^)]+))?/) ) {
-            $self->{defaults}->{$long} = defined $def ? $def : 1;
+            $def = defined $def ? $def : 1;
+            $def = $def eq 'yes' ? 1 : $def eq 'no' ? 0 : $def;
+            $self->{defaults}->{$long} = $def;
             PTDEBUG && _d($long, 'default:', $def);
          }
 
@@ -1255,6 +1257,10 @@ sub get_opts {
       }
    }
 
+   if ( exists $self->{opts}->{'buffer-stdout'} && $self->{opts}->{'buffer-stdout'}->{got} ) {
+      STDOUT->autoflush(1 - $self->{opts}->{'buffer-stdout'}->{value});
+   }
+
    if ( @ARGV && $self->{strict} ) {
       $self->save_error("Unrecognized command-line options @ARGV");
    }
@@ -5757,7 +5763,7 @@ sub version_check {
       PTDEBUG && _d('Version check failed:', $EVAL_ERROR);
    }
 
-   if ( @$instances_to_check ) {
+   if ( $instances_to_check and @$instances_to_check ) {
       eval {
          update_check_times(
             instances => $instances_to_check,
@@ -7763,6 +7769,13 @@ The danger is that a crash might cause lost data.
 The performance increase I have seen from using L<"--buffer"> is around 5 to 15
 percent.  Your mileage may vary.
 
+=item --[no]buffer-stdout
+
+default: yes
+
+Enables STDOUT buffering. Disable this option if you want to see live progress
+when using output post-processing tools such as C<tee> or C<kubectl logs>.
+
 =item --bulk-delete
 
 Delete each chunk with a single statement (implies L<"--commit-each">).
@@ -8102,6 +8115,12 @@ until the replica is caught up, then proceeds to fetch and archive the row.
 
 This option may eliminate the need for L<"--sleep"> or L<"--sleep-coef">.
 
+=item --mysql_ssl
+
+short form: -s; type: int
+
+Create SSL MySQL connection.
+
 =item --no-ascend
 
 Do not use ascending index optimization.